Article sortation system

Abstract

An article sortation system includes a plurality of transport units which are movable along a conveying path between induction stations and discharge stations along each side of the conveying path. Each transport unit has side by side loading and support capability and is operable to receive packages from induction stations and discharge the packages at an appropriate discharge station. The system includes a control which determines the destination of articles and resolves blocking conditions between articles at the induction stations or at the transport units. The system may include a reinduction station for receiving an article from a transport unit and reinducting the article onto a transport unit, in order to resolve a blocking condition between a pair of articles on the respective transport unit.

1. A method for induction of articles onto one or more of a plurality of transport units having side by side article support capability, the transport units being movable along a continuous conveying path, said method comprising:
 providing at least one induct for loading articles onto the transport units; 
 determining a destination of articles at said at least one induct; 
 loading articles from said at least one induct to the transport units, wherein loading articles comprises loading two articles from said at least one induct onto a respective one of said transport units as said transport unit moves past said at least one induct, said two articles at least occasionally having different destinations; 
 providing at least one reinduction station downstream from said at least one induct and upstream of the destinations of the articles; 
 determining at least partial blocking conditions between two articles loaded on a respective transport unit, said at least partial blocking conditions comprising an interference between two articles based on the destination of the two articles and the side of the transport unit at which the two articles are positioned; and 
 resolving at least some of said at least partial blocking conditions by discharging one of the two articles to said at least one reinduction station and reinducting that one article from said at least one reinduction station onto a subsequent transport unit. 
 
     
     
       2. The method of  claim 1 , wherein resolving at least some of said at least partial blocking conditions includes resolving at least some of said at least partial blocking conditions as a function of an availability status of said at least one reinduction station. 
     
     
       3. The method of  claim 1 , wherein providing at least one induct includes providing at least two inducts at opposite sides of the conveying path. 
     
     
       4. The method of  claim 3 , wherein loading articles includes loading articles from said at least two inducts as a function of an induction priority status of said at least two inducts. 
     
     
       5. The method of  claim 1  including unloading articles at destinations at opposite sides of the conveying path. 
     
     
       6. The method of  claim 1 , wherein the transport units include side by side article supports which are independently operable to load, unload or transfer articles. 
     
     
       7. The method of  claim 1 , including feeding articles to said at least one induct irrespective of the destination of the articles. 
     
     
       8. An article sortation system for inducting articles onto one or more of a plurality of transport units having side by side article support capability, the transport units being movable along a continuous conveying path, said article sortation system comprising:
 at least one induct for loading articles onto the transport units, said at least one induct being positionable along the conveying path; 
 a control which is operable to identify articles and determine a destination of articles at said at least one induct; 
 at least one reinduction station positionable downstream from said at least one induct and upstream of the destinations of the articles; 
 said article sortation system loading articles onto said transport units as said transport units move past said at least one induct, said article sortation system at least occasionally loading two articles onto one of said transport units with the two articles having different destinations; and 
 wherein said control is further operable to determine at least partial blocking conditions between the two articles loaded onto a respective transport unit, said at least partial blocking conditions comprising an interference between the two articles based on the destination of the two articles and the side of the transport unit at which the two articles arc positioned, said control being further operable to resolve at least some of said at least partial blocking conditions by discharging one of the two articles to said at least one reinduction station and reinducting that one article from said at least one reinduction station onto a subsequent transport unit. 
 
     
     
       9. The article sortation system of  claim 8 , wherein said control is operable to resolve at least some of said at least partial blocking conditions as a function of an availability status of said at least one reinduction station. 
     
     
       10. The article sortation system of  claim 8 , wherein said at least one induct comprises at least two inducts positionable at opposite sides of the conveying path. 
     
     
       11. The article sortation system of  claim 10 , wherein said control is operable to load articles from said at least two inducts in response to an induction priority status of said at least two inducts. 
     
     
       12. The article sortation system of  claim 8 , wherein said control is operable to unload articles at destinations at opposite sides of the conveying path. 
     
     
       13. The article sortation system of  claim 8 , wherein the transport units include side by side article supports which are independently operable to load, unload or transfer articles. 
     
     
       14. The article sortation system of  claim 8 , wherein said at least one induct is operable to receive articles irrespective of the destination of the articles.